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(11) | EP 2 922 178 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Motor |
| (57) A rotating portion of a motor includes a plurality of magnets arranged in a circumferential
direction about a central axis, and a rotor core arranged to hold the magnets. The
magnets include two or more magnet pairs. Each magnet includes a pair of long sides
and a pair of short sides. The pair of long sides are magnetized to have mutually
different polarities. Within each magnet pair, magnetic poles of the same polarity
are arranged circumferentially opposite to each other. A corner of each magnet of
each magnet pair, the corner lying on a short-side side closer to the central axis
and on a side closer to the other magnet of the magnet pair, is arranged in a separate
one of flux barriers defined in the rotor core. End points of a boundary between each
magnet and a corresponding one of the flux barriers lie on one of the pair of long
sides which includes the corner and on one of the pair of short sides which includes
the corner or another one of the pair of long sides. The rotor core includes an outer
core portion, an inner core portion, and a joining portion arranged to join the outer
core portion and the inner core portion to each other between flux barriers of a flux
barrier pair. The joining portion is arranged to have a minimum circumferential width
smaller than the length of each short side.
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